Workers from the ant species Harpegnathos saltator can convert to reproductive pseudoqueens (gamergates) that lay eggs, have a dramatically expanded lifespan, and specific behaviors. This transition can be achieved by two paths: social and solitary. In the social path, workers from a colony where the queen has died interact through antennal dueling until several winners become gamergates; in the solitary path, an isolated worker can also lay eggs. Social and solitary gamergates have striking differences in behavior. Importantly, it is much more difficult to revert social gamergates to workers than solitary, suggesting that social interactions allow the establishment of more stable epigenetic marks than in solitary gamergates. We will use this unique tool to investigate how social interactions influence epigenetic processes and how changes in epigenetic modifications stabilize behavioral patterns. We also propose to develop genetic tools in H. saltator using powerful gene-targeting approaches, notably CRISPR, to modulate these epigenetic marks and potentially behavior. These pilot studies will lay a foundation for further functional analyses tha will advance our understanding of epigenetic underpinnings of behavior.